usb: export firmware version

Remove the meaningless version string in iSerialNumber, which was incorrect
since this string should be unique to a device if it exists.

Export the firmware version string as the configuration string, so it's
traceable to a given firmware build/sources.

Signed-off-by: Vincent Palatin <vpalatin@chromium.org>

BRANCH=samus
BUG=none
TEST=make buildall
from a workstation, do "sudo lsusb -v" and see the full version string
exported as the configuration name.

Change-Id: I557df2936421e2926ac0fc0003888370cec3e201
Reviewed-on: https://chromium-review.googlesource.com/222877
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>
Commit-Queue: Vincent Palatin <vpalatin@chromium.org>
Tested-by: Vincent Palatin <vpalatin@chromium.org>

7 files changed, 21 insertions, 7 deletions

diff --git a/board/discovery-stm32f072/echo.c b/board/discovery-stm32f072/echo.c
index ec7353e43e..08550a4b36 100644
--- a/board/discovery-stm32f072/echo.c
+++ b/board/discovery-stm32f072/echo.c
@@ -43,7 +43,7 @@ const void *const usb_strings[] = {
 	[USB_STR_DESC]    = usb_string_desc,
 	[USB_STR_VENDOR]  = USB_STRING_DESC("Google Inc."),
 	[USB_STR_PRODUCT] = USB_STRING_DESC("discovery-stm32f072"),
-	[USB_STR_VERSION] = USB_STRING_DESC("v1.0"),
+	[USB_STR_VERSION] = NULL /* filled at runtime */,
 };
 
 BUILD_ASSERT(ARRAY_SIZE(usb_strings) == USB_STR_COUNT);
diff --git a/board/fruitpie/board.c b/board/fruitpie/board.c
index 800fedea96..cd733c6c8f 100644
--- a/board/fruitpie/board.c
+++ b/board/fruitpie/board.c
@@ -67,7 +67,7 @@ const void * const usb_strings[] = {
 	[USB_STR_DESC] = usb_string_desc,
 	[USB_STR_VENDOR] = USB_STRING_DESC("Google Inc."),
 	[USB_STR_PRODUCT] = USB_STRING_DESC("FruitPie"),
-	[USB_STR_VERSION] = USB_STRING_DESC("v1.0"),
+	[USB_STR_VERSION] = NULL /* filled at runtime */,
 };
 BUILD_ASSERT(ARRAY_SIZE(usb_strings) == USB_STR_COUNT);
 
diff --git a/board/hoho/board.c b/board/hoho/board.c
index 598768ee6d..c521d2c6f8 100644
--- a/board/hoho/board.c
+++ b/board/hoho/board.c
@@ -86,7 +86,7 @@ const void * const usb_strings[] = {
 	[USB_STR_DESC] = usb_string_desc,
 	[USB_STR_VENDOR] = USB_STRING_DESC("Google Inc."),
 	[USB_STR_PRODUCT] = USB_STRING_DESC("Hoho"),
-	[USB_STR_VERSION] = USB_STRING_DESC("v0.001"),
+	[USB_STR_VERSION] = NULL /* filled at runtime */,
 	[USB_STR_BB_URL] = USB_STRING_DESC(USB_GOOGLE_TYPEC_URL),
 };
 BUILD_ASSERT(ARRAY_SIZE(usb_strings) == USB_STR_COUNT);
diff --git a/board/twinkie/board.c b/board/twinkie/board.c
index 07faadd11b..69fe2735b2 100644
--- a/board/twinkie/board.c
+++ b/board/twinkie/board.c
@@ -73,7 +73,7 @@ const void * const usb_strings[] = {
 	[USB_STR_DESC] = usb_string_desc,
 	[USB_STR_VENDOR] = USB_STRING_DESC("Google Inc."),
 	[USB_STR_PRODUCT] = USB_STRING_DESC("Twinkie"),
-	[USB_STR_VERSION] = USB_STRING_DESC("v0.001"),
+	[USB_STR_VERSION] = NULL /* filled at runtime */,
 	[USB_STR_SNIFFER] = USB_STRING_DESC("USB-PD Sniffer"),
 };
 BUILD_ASSERT(ARRAY_SIZE(usb_strings) == USB_STR_COUNT);
diff --git a/chip/stm32/usb.c b/chip/stm32/usb.c
index d4ad8e48ea..a43c63905b 100644
--- a/chip/stm32/usb.c
+++ b/chip/stm32/usb.c
@@ -44,7 +44,7 @@ static const struct usb_device_descriptor dev_desc = {
 	.bcdDevice = 0x0200, /* 2.00 */
 	.iManufacturer = USB_STR_VENDOR,
 	.iProduct = USB_STR_PRODUCT,
-	.iSerialNumber = USB_STR_VERSION,
+	.iSerialNumber = 0,
 	.bNumConfigurations = 1
 };
 
@@ -55,7 +55,7 @@ const struct usb_config_descriptor USB_CONF_DESC(conf) = {
 	.wTotalLength = 0x0BAD, /* no of returned bytes, set at runtime */
 	.bNumInterfaces = USB_IFACE_COUNT,
 	.bConfigurationValue = 1,
-	.iConfiguration = 0,
+	.iConfiguration = USB_STR_VERSION,
 	.bmAttributes = 0x80, /* bus powered */
 	.bMaxPower = 250, /* MaxPower 500 mA */
 };
@@ -121,7 +121,12 @@ static void ep0_rx(void)
 			if (idx >= USB_STR_COUNT)
 				/* The string does not exist : STALL */
 				goto unknown_req;
-
+			if (idx == USB_STR_VERSION) {
+				/* use the generated firmware version string */
+				desc = usb_fw_version;
+				len = desc[0];
+				break;
+			}
 			desc = usb_strings[idx];
 			len = desc[0];
 			break;
diff --git a/common/version.c b/common/version.c
index 766b4ad56b..a80d843580 100644
--- a/common/version.c
+++ b/common/version.c
@@ -6,7 +6,9 @@
 /* Embed firmware version number in the binary */
 
 #include <stdint.h>
+#include "common.h"
 #include "ec_version.h"
+#include "usb.h"
 #include "version.h"
 
 const struct version_struct version_data
@@ -19,6 +21,11 @@ const struct version_struct version_data
 const char build_info[] __attribute__((section(".rodata.buildinfo")))  =
 	CROS_EC_VERSION " " DATE " " BUILDER;
 
+#ifdef CONFIG_USB
+/* UTF-16 encoded USB string descriptor */
+const void * const usb_fw_version = USB_STRING_DESC(CROS_EC_VERSION32);
+#endif
+
 uint32_t ver_get_numcommits(void)
 {
 	int i;
diff --git a/include/usb.h b/include/usb.h
index ffbdf37c27..53e53939d7 100644
--- a/include/usb.h
+++ b/include/usb.h
@@ -257,6 +257,8 @@ static inline void memcpy_usbram(usb_uint *ebuf, const uint8_t *src, int size)
 /* These descriptors defined in board code */
 extern const void * const usb_strings[];
 extern const uint8_t usb_string_desc[];
+/* USB string descriptor with the firmware version */
+extern const void * const usb_fw_version;
 extern const struct bos_context bos_ctx;
 
 /* Helpers for endpoint declaration */